Net metering is a policy by many states in the United States designed to help the adoption of renewable energy. Net metering was pioneered in the United States as a way to allow solar and wind to provide electricity whenever available and allow use of that electricity whenever it was needed, beginning with utilities in Idaho in 1980, and in Arizona in 1981. In 1983, Minnesota passed the first state net metering law. As of March 2015, 44 states and Washington, D.C. have developed mandatory net metering rules for at least some utilities. However, although the states' rules are clear, few utilities actually compensate at full retail rates. Net metering policies are determined by states, which have set policies varying on a number of key dimensions. The Energy Policy Act of 2005 required state electricity regulators to "consider" (but not necessarily implement) rules that mandate public electric utilities make net metering available to their customers upon request. Several legislative bills have been proposed to institute a federal standard limit on net metering. They range from H.R. 729, which sets a net metering cap at 2% of forecasted aggregate customer peak demand, to H.R. 1945, which has no aggregate cap, but does limit residential users to 10 kW, a low limit compared to many states, such as New Mexico, with an 80,000 kW limit, or states such as Arizona, Colorado, New Jersey, and Ohio, which limit as a percentage of load. Policies by state Arizona, California, Colorado, Connecticut, Delaware, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Ohio, Oregon, Pennsylvania, Utah, Vermont, and West Virginia are considered the most favorable states for net metering, as they are the only states to receive an "A" rating from Freeing the Grid in 2015. Regulators in multiple states are acting as "referees" in debates between utility companies and advocates of distributed resources, such as solar panel arrays. In 2016 the National Association of Regulatory Utility Commissioners (NARUC) published the Manual on Distributed Energy Resources Compensation as a way to help states decide on rate structures dealing with homes and businesses that generate their own power and send excess power back to the electric grid. The intention behind the manual is to "provide a consistent framework for evaluating rate design decisions in the age of distributed energy resources." The president of NARUC, when he commissioned the manual, said his instructions to the committee writing the